Refrigerant compressor construction

ABSTRACT

A refrigerant compressor having an improved crankcase construction in the form of a pair of spaced-apart channel members having cylinders secured thereto, the channel members interconnected so as to support the stator of the electric drive motor of the compressor.

United States Patent Ellis et al.

[ Oct. 2, 1973 REFRIGERANT COMPRESSOR CONSTRUCTION Inventors: Charles B. Ellis; Sidney A. Parker,

both of Fort Worth, Tex.

Assignee: Lennox Industries Inc., Marshalltown, Iowa Filed: Dec. 23, 1971 Appl. No.: 211,242

US. Cl 417/360, 308/31, 417/902 Int. Cl. F041) 17/00, F04b 35/00 Field of Search 417/415, 360, 902;

References Cited UNITED STATES PATENTS 7/1959 Hintze 417/902 X 2,628,765 2/1953 Anderson 417/902 X 1,831,857 11/1931 Goodnoww. 2,310,282 2/1943 Gauss 308/31 FORElGN PATENTS OR APPLICATIONS 8/1962 Germany 417/415 Primary ExaminerCarlton R. Croyle Assistant Examiner-Richard Sher AttorneyA. W. Molinare et al.

[57] ABSTRACT A refrigerant compressor having an improved crankcase construction in the form of a pair of spaced-apart channel members having cylinders secured thereto, the channel members interconnected so as to support the stator of the electric drive motor of the compressor.

10 Claims, 6 Drawing Figures PATENTEUUET 2mm sum 10? 2 INVENTOR5" CHARLES B. ELLIS ATT'YS PATENTED 3 SHEET 2 BF 2 1. \BVJORSJ CHARLES S ELLIS SIDNEY A PARKER ATT'YS REFRIGERANT COMPRESSOR CONSTRUCTION SUMMARY OF THE INVENTION This invention relates to a refrigerant reciprocating compressor, and more particularly to an improved crankcase arrangement for such compressors.

Heretofore, it has been customary to form compressor crankcases of castings having a portion with cylinders defined therein and a portion defining a supporting annular sleeve for the stator of the electric drive motor. A disadvantage of a cast crankcase structure is that it is heavy due to the necessity for relatively thick walls to provide desired strength, thus making the overall compressor heavy. Further, considerable machining is required on a large number of different surfaces. There is difficulty in removing all of the sand from the casting and particularly from the suction annulus and the discharge annulus within the compressor, causing both machining problems in manufacture and contamination problems in subsequent use. The cost of the casting and the machining of same is expensive.

More recently, it has been suggested that the cast crankcase be replaced by a crankcase assembly formed by components of sheet metal stampings secured together by hydrogen brazing or chemical adhesives to define the complete assembly, see, for example, US. Pat. Nos. 3,385,515 and 3,403,847. Such construction is lighter in weight and machining of parts is facilitated.

An object of this invention is to provide a further improved crankcase construction embodying a channel member formed from sheet metal, which is simpler in configuration than prior known crankcase constructions.

Another object of the present invention is to provide an improved refrigerant compressor having a sheet metal crankcase structure in the form of a channel member having a base connecting a pair of upstanding arms and an intermediate member or bottom member secured to the upstanding arms and spaced from the base, with the intermediate member having provision thereon for suitably supporting the stator and positioning the rotor of the electric drive motor of the compressor.

It is another object of this invention to provide an improved refrigerant compressor having a sheet metal crankcase structure comprising a base portion connecting a pair of upright arms and a bottom member secured to the upright arms, with portions struck out from the upstanding arms for suitably positioning the stator of the electric drive motor.

Still another object of this invention is to provide an improved refrigerant compressor having spaced channel members interconnected so as to support the stator of the electric drive motor of the compressor.

Yet another object of this invention is to provide an improved refrigerant compressor having channel support members for securing the stator of a non-circular electric drive motor, with means for adjusting the shaft bearing to permit alignment of same with the central axis of the stator. Other objects and advantages of the present invention will become more apparent hereafter.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a cross-sectional elevation view with parts broken away of a complete refrigerant compressor assembly embodying the present invention;

FIG. 2 is a cross-sectional view taken generally along line 22 of FIG. 1;

FIG. 3 is a plan view of the channel member of the present invention;

FIG. 4 is a cross-sectional view of the channel member taken generally along line 4-4 of FIG. 3;

FIG. 5 is a cross-sectional view of a modified design illustrating use of a non-circular stator in a compressor electric drive motor; and

FIG. 6 is a cross-sectional elevation view of a modified refrigerant compressor embodying principles of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT A complete refrigerant compressor 10 embodying the invention is shown in FIGS. 1 and 2. Such compressor 10 comprises a gas-tight housing formed by an upper shell 11 and a lower shell 12, each of which is generally cup-shaped. The shells 11 and 12 are joined to one another by welding or the like. Projections or legs (not shown) are secured to the bottom of the lower shell 12 for mounting the compressor 10 in an upright manner in an air-conditioning unit or a condensing unit.

Supported within the outer housing or casing of the compressor 10 by suitable means 9 is the compression mechanism which includes the crankcase structure 14. The crankcase structure 14 includes a base 13 and a pair of upstanding channel members 16 and 18, each generally U-shaped in cross-section. The support means 9 may comprise a spring disposed between lugs or brackets on the crankcase structure and outer casing, as is conventional in the art. Each of the inwardly facing upstanding members 16 and 18, respectively, has an opening and 17 therein for receiving a cylinder 20 and 22, respectively. In the embodiment of FIGS. 1-4, a two-cylinder compressor is shown. It will be understood that principles of this invention may be adapted to compressors with other cylinder configurations. As illustrated, the cylinders 20 and 22 are retained in place on the crankcase structure 14 by means of shoulders on the exterior of each cylinder 20, 22 engaging the outside surface of the members 16 and 18 and retaining ring means 26 and 28 engaging a recess in the cylinders 20, 22 and abutting the inside surface of the members 16 and 18. Movable within each cylinder 20 and 22 is a piston 30. Each piston 30 is secured by means of a connecting rod 36, 37 to a drive shaft 32 centrally joumalled in the compression mechanism. Suitably connected to the drive shaft as, for example, by electron beam welding, is a flywheel 33 and an eccentric 34.

The crankcase structure includes a bearing plate 39 adjustably secured to the base 13 as, for example, by bolts and a bearing hub 38 supported by the bearing plate 39 and retaining a bearing liner 38 that journals the lower end of the drive shaft 32. The entry plate 41 which functions as a thrust plate for shaft 32 has an opening that provides an inlet to the interior of the hollow drive shaft 32 and is connected to hearing plate 39 by means of bolts'43. Bearing plate 39 substantially closes the opening 19 in base 13 and is adjustable laterally of the axis of the drive shaft which coincides with the axis of the stator to properly align bearing 38' with the axis of the stator of the electric drive motor 50. Bolts 40 extend through holes in plate 39 that are larger than the diameter of the bolts to permit lateral adjustment of the plate. After adjustment, the bolts 40 are tightened to retain the plate 39 in desired adjusted posi tion. Plate 45' is similarly adjustable. it will be understood that in use, rotation of the drive shaft 32 will cause lubricant (oil) contained in the sump 62 formed in the lower portion of shell or casing portion 12 to be ingested through the opening in plate 41 into the axially extending passage in drive shaft 32. Oil then flows through radial ports or openings in the drive shaft 32 to lubricate the bearing surfaces.

An intermediate member 42 forms part of the crankcase structure 14 and is secured to the upstanding portions 16 and 18 at a'distance spaced above the base 13. The intermediate member 42, which is generally cupshaped, is secured to the upstanding member 16, 18 for example/by welding or brazing. A centrally disposed opening 44 is provided in the member 42 for receiving a bearing support 46 that carries bearings or bearing liners 47 and 48 that journal the intermediate portion of the drive shaft 32. Bearing support 46 is connected to plate 45' that is adjustably supported to plate 42 by bolts 45 to permit alignment of bearings 47, 48 with the axis of the stator of motor 50.

The top annular surface indicated at 59 of the intermediate member 42 functions as a stop for properly positioning the stator of the electric drive motor 50 which is provided for rotating the drive shaft 32. The electric drive motor 50 includes a rotor 52 suitably secured to the upper portion of the drive shaft 32 (for example by a force fit) and a stator 54 secured in place within the crankcase structure and inductively connected to the rotor for actuating same. The fastening means for securing the stator to the crankcase structure includes machine screws or bolts 67, butmay not be required depending upon the design.

Within the ends of the cylinders 20 and 22 are disposed valve units 56 and 58 which function in conventional fashion to control flow of gas through the cylinders. Cylinder heads 57, 57' close the end of the cylinders 20, 22 and retain the valve units in place.

A return line or suction line 60 from a refrigerant system communicates vaporous refrigerant from the refrigeration system back to the interior of the compressor. Gas entering the space 64 between the compression mechanism and the interior of the outer housing passes into the cylinder 20 via an inlet opening 65. The returning suction gas compressed within the cylinder 20 is discharged through a line 66 into a discharge muffler 68 and then into a conduit 69 and a tee connection 70 for discharge to the refrigeration system. Similarly, refrigerant passes from space 64 through the passage inlet opening 65' into the cylinder 22 and after compression through the line 72 into the discharge muffler 74. From the discharge muffler 74 the gas flows through a conduit 75 to the tee connection 70 for discharge from the compressor into the discharge line of a refrigeration system.

The adjustability of the bearings for drive shaft 32 is particularly important where a motor having a noncircular stator is used. In FIG. 5, there is shown a motor 50' having a non-circular stator 54' inductively driving rotor 52'. Rotor 52 is secured to shaft 32 for actuating same. Circular stators are generally machined to size and thus the dimensions and alignment of outside diameter (o.d.) and inside diameter (i.d.) are held to close tolerances. Alignment of the shaft bearings with the axis of the stator and rotor is not as severe a problem in motors having circular stators as it is with noncircular stators, which are not formed with precise exterior dimensions. The bearing adjustability provided by adjustment bearing plates 39 and 45' enables desired alignment of the bearings with the central axis of the motor i.d. and drive shaft.

The crankcase structure is fabricated from stock sheet material. The holes for the cylinders and crankshaft or drive shaft are punched in the sheet material, which is then formed to shape. The cylinders are positioned in an opening in the upright channel portions of the crankcase structure and locked in place with suitable fastening means, for example retaining rings. The stator of the electric drive motor is secured in place between the upright channel members. With reference to FIG. 1, the upper shaft bearing means is secured to the cap or plate 45, which is adjustably secured to the intermediate member 42 of the crankcase structure. The lower shaft bearing is similarly secured to the end cap or end plate 39 which is adjustably connected to the base 13.. The pistons are positioned in the cylinders and the drive shaft is positioned in the crankcase structure, operatively affixed to the connecting rods for driving the pistons and with the rotor secured to the upper end thereof and disposed within the stator so as to be inductively driven thereby.

Turning to FIG. 6, there is shown a modified refrigerant compressor embodying principles of this invention. Compressor differs from compressor 10 essentially in that the outer housing configuration is different and the crankcase structure 114 is inverted as compared with crankcase structure 14. Crankcase structure 114 includes a base 113 and depending channel members 116 and 118. Cylinders 120 and 122 are retained in openings in the channel members by retaining ring means 126 and 128. Within each cylinder is a piston 130 and 130' operatively driven by drive shaft 132 through connecting rod 136,137.

Shaft 132 is journalled at its upper end in bearing 138' held in bearing hub or support 138. The bearing 7 hub 138 is secured to plate 139 that is adjustably secured to base 113 by bolts or machine screws 140. Bolts or machine screws 143 connect plate 141 to the plate 139.

Struck-out portions 159 in the depending channel members provide upper stops for positioning the stator 154 of motor properly within the crankcase structure 114. Bearing support member is disposed between the bottom of stator 154 and the bottom of compressor outer shell 112. Closure plate 180 is adjustably connected to out-turned flanges 182, 184 on members 116, 118 by bolts or machine screws 18S. Bearing hub secured centrally in plate 180 contains bearing 191 which journals the lower end of drive shaft 132. There is an inlet opening 194 in the bottom of the bearing hub 190 to permit entry of oil from the sump to the interior of the drive shaft 132. During rotation of shaft 132 oil will be ingested from the sump through the inlet opening 194 and pumped to the connecting rod bearing surfaces and drive shaft bearing surfaces.

The crankcase structure or support means 114 is supported with the outer housing by means of an annular intermediate member 196 secured at its outer periphery to the outer housing at the junction of upper shell 1 1 1 and lower shell 1 12. At its inner end the intermediate member 196 is formed with an annular flange 197 that is connected to the depending members 116, 118 in a suitable fashion, for example by welding.

Further description of the function of the compressor of FIG. 6 is believed unnecessary and reference may be made to the description of the compressor of FIGS. l-4 if desired.

Suction gas enters the cylinders 120 and 122 through openings 165. The refrigerant gas is compressed by pistons (130 being shown) within the cylinders and discharged through the valve units (158 being shown) through conduits 1166 and 172, respectively, to discharge muffling means and then to the discharge line that communicates with the refrigeration system. The pistons in the cylinders are operatively connected to the eccentric 133 on drive shaft 132 through connecting rods.

There has been provided by the present invention an improved refrigerant compressor crankcase structure fabricated from a metal channel-like member having a base, a pair of channel members, and stop means for positioning the stator of the electric drive motor in such compressor relative to the channel-like member. The channel-like member is preferably formed from a sheet of metal suitably stamped and then drawn to form. Fabrication of the channel-like member is relatively inexpensive and fabrication of a compressor including such channel-like member is relatively simple.

While presently preferred embodiments of the invention have been disclosed, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention and, therefore, it is intended in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of this invention.

We claim:

1. In a refrigerant compressor comprising an outer casing, support means within said casing, means for supporting the support means within said outer casing, at least one cylinder on said support means, a piston slidable in said cylinder, a drive shaft journalled in said support means and operatively connected to said piston for actuating said piston, and an electric motor for rotating said drive shaft, said motor including a stator secured to the support means and a rotor secured to the drive shaft, the improvement characterized by said support means comprising a structure having a base and spaced-apart portions comprising inwardly facing channel like members, said cylinder being secured transversely to a spaced-apart portion, and intermediate stop means on said spaced-apart portions at a distance from said base to aid in positioning the stator of the electric motor, said stator being secured by said spaced-apart portions.

2. A refrigerant compressor as in claim 1 wherein the base has an opening therein and first bearing means is secured to said support means in position to journal an end of said drive shaft therein.

3. A refrigerant compressor as in claim 2 including an intermediate member having a centrally disposed opening therein secured to the spaced-apart portions, and second bearing means in said centrally-disposed opening in the intermediate member for journalling the drive shaft intermediate its ends.

4. A refrigerant compressor as in claim 2 wherein the first bearing means is adjustably secured to the support means for movement transverse to the central axis of the stator.

5. A refrigerant compressor as in claim 3 wherein the second bearing means is adjustably supported for movement transverse to the central axis of the stator.

6. A refrigerant compressor as in claim 1 wherein the base is disposed at the top and the spaced-apart portions depend from the base.

7. A refrigerant compressor as in claim 1 wherein the base is disposed at the bottom and the spaced-apart portions extend upwardly from the base.

8. A refrigerant compressor as in claim 1 wherein the stator is circular and fastening means affix the spacedapart portions to the stator.

9. A refrigerant compressor as in claim 1 wherein the stator is non-circular, and fastening means affix the spaced-apart portions to the stator.

10. A refrigerant compressor as in claim 9 wherein Y the fastening means comprise machine screws. 

1. In a refrigerant compressor comprising an outer casing, support means within said casing, means for supporting the support means within said outer casing, at least one cylinder on said support means, a piston slidable in said cylinder, a drive shaft journalled in said support means and operatively connected to said piston for actuating said piston, and an electric motor for rotating said drive shaft, said motor including a stator secured to the support means and a rotor secured to the drive shaft, the improvement characterized by said support means comprising a structure having a base and spaced-apart portions comprising inwardly facing channel like members, said cylinder being secured transversely to a spaced-apart portion, and intermediate stop means on said spaced-apart portions at a distance from said base to aid in positioning the stator of the electric motor, said stator being secured by said spaced-apart portions.
 2. A refrigerant compressor as in claim 1 wherein the base has an opening therein and first bearing means is secured to said support means in position to journal an end of said drive shaft therein.
 3. A refrigerant compressor as in claim 2 including an intermediate member having a centrally disposed opening therein secured to the spaced-apart portions, and second bearing means in said centrally-disposed opening in the intermediate member for journalling the drive shaft intermediate its ends.
 4. A refrigerant compressor as in claim 2 wherein the first bearing means is adjustably secured to the support means for movement transverse to the central axis of the stator.
 5. A refrigerant compressor as in claim 3 wherein the second bearing means is adjustably supported for movement transverse to the central axis of the stator.
 6. A refrigerant compressor as in claim 1 wherein the base is disposed at the top and the spaced-apart portions depend from the base.
 7. A refrigerant compressor as in claim 1 wherein the base is disposed at the bottom and the spaced-apart portions extend upwardly from the base.
 8. A refrigerant compressor as in claim 1 wherein the stator is circular and fastening means affix the spaced-apart portions to the stator.
 9. A refrigerant compressor as in claim 1 wherein the stator is non-circular, and fastening means affix the spaced-apart portions to the stator.
 10. A refrigerant compressor as in claim 9 wherein the fastening means comprise machine screws. 